The largest prefecture

When I was a high school student, I went on a school trip in Hokkaido. It took about 2hours from Osaka to Hokkaido. I went there in June, so it was cool for me enough to feel comfortable. I experienced rafting for the first time in Hokkaido. Going through the river, the instructor of our group dropped us one after another. When I fell down the river, I felt so cold and I thought the river in June was very very cold. It is too early to swim in the river in Hokkaido in June, I think!!!!!!!!